With the ever-increasing demand for wireless transmission capacity based on the number of users able to access a system or the speed at which data is transferred, multiple input multiple output (MIMO) architectures have evolved. MIMO architectures incorporate multiple antennas for transmission and multiple receivers for reception. In combination with various coding techniques, the spatial diversity provided by MIMO systems provides for significant increases in the number of users that can access a system at any given time, as well as the amount of data that can be transmitted over a given period of time. Unfortunately, the nature of mobile communications dictates the need for inexpensive user elements, such as mobile telephones, wireless personal digital assistants (PDAs), and the like. Implementing multiple antennas and transmission paths within user elements significantly increases their complexity, and thus price. For certain applications, the price associated with providing multiple antennas and transmission paths in user elements has significantly outweighed the benefit of more capacity. In other applications, the benefits of MIMO-based communications warrant providing multiple antennas and transmission paths.
Most base stations are already equipped with multiple antennas and receivers, and given the nature of such infrastructure, the cost of providing such has proven largely insignificant. Thus, there exists a wireless infrastructure capable of facilitating MIMO-based communication, yet certain consumers are unwilling to bear the cost of completing the MIMO environment by buying properly equipped user elements. As such, there is a need to reap the benefit of MIMO-based communications without requiring all user elements to have multiple antennas and transmission paths. There is a further need to provide more efficient and effective ways to facilitate MIMO-based communications between base stations and different types of user elements.